How shipment density determines freight classification and shipping costs.
In Less-Than-Truckload (LTL) shipping, freight class is a standardized classification system created by the National Motor Freight Traffic Association (NMFTA). It categorizes commodities into 18 distinct classes ranging from Class 50 to Class 400 based on four key metrics: density, stowability, handling, and liability.
Density (measured in pounds per cubic foot) is the single most important factor. Heavier, compact freight takes up less volume relative to its weight, making it cheaper to transport per pound.
| Density Range (lbs / cu ft) | Estimated Freight Class | Typical Cargo Examples |
|---|---|---|
| Over 50 lbs | Class 50 | Steel plates, heavy machinery parts |
| 15 to 22.5 lbs | Class 70 | Automotive parts, boxed goods |
| 8 to 10 lbs | Class 100 | Palletized electronics, framed artwork |
| 4 to 6 lbs | Class 175 | Furniture, large plastic fixtures |
| Less than 1 lb | Class 400 | Light bulbs, ping pong balls, uncompressed foam |